Perhaps I'm slow.... because this is a fairly new thought to me.
I write and post information about ancestors on my blog.
People (sometimes) search for the ancestors whose names I post.
They contact me and a connection is made.
I don't post ancestors on my blog if I have too little or uncertain information.
People (possibly) search for the ancestors I haven't posted.
But I would never know it and they would never find my ancestor and me on this blog through a search engine.
Therefore, no connection is made.
Best to post a name with whatever information I have than not post an ancestor's name at all. Someone else may be searching for the same person.